The Realistic Portavision - Portable Television in the 1980s

About a week or two ago on this blog, I may have foreshadowed that I had acquired a new electronic item worth talking about.  Portable televisions have always been of interest to me.  Since TVs became mainstream in the 1950s, marketers have always tried to find ways to make TVs smaller and able to be used in more and more places across the globe.  My little acquisition represents the peak of its technology for its time, so let's look at it in greater detail.

The system in question is called the Realistic Portavision.  Its most notable feature is that it is a fully portable color CRT TV.  A sticker on the back of the unit stated it was manufactured in November of 1985.  During the 1980s, portable TVs were not particularly rare.  Many kitchens and campers featured one.  But these TVs were typically black and white TVs.  Black and white TVs were much cheaper to manufacture, required fewer components to make them work and consumed less energy. Black and white TVs in portable sizes were quite common by the mid-1970s and were manufactured throughout the 1980s.

Practical Issues with a Tandy 1400 LT Laptop Comptuer

Recently I acquired a Tandy 1400 LT Laptop computer, so as tradition seems to demand, I will talk about my impressions of the machine, tips on how to use it and mistakes to avoid.  The Tandy 1400 LT is Tandy's first IBM PC compatible laptop.  As the 1400 LT is so very much a mostly-improved clone of the IBM PC Convertible, it makes sense to compare the two products.

In April of 1986, IBM released the first PC compatible that could conceivably be called a laptop, the IBM PC Convertible Model 5140.  In 1988, Tandy released its own version of the PC laptop, the Tandy 1400 LT.  The Tandy machine had many notable improvements over the IBM machine :

Sierra's Short-Lived Tandy Color Computer Support

In 1980 Radio Shack released its budget line of computers with the Tandy TRS-80 Color Computer.  Originally priced for $399.00 for the base model, it came with a 6809 CPU running at .894MHz, 4K of RAM and could display only upper case characters.  It could be expanded to 16KB, then 32KB and finally 64KB.  It had a built-in BASIC, a cartridge slot, two joysticks and a 53-key keyboard.  Its most often used graphics mode was a 256x192 artifact mode capable of four primary colors (black, white, blue and orange). It used single sided, double density 5.25" drives that held 156,672 bytes per side for user data using Radio Shack DOS.  Its sound hardware was a 6-bit DAC and it had a serial port and a cassette port.  The Color Computer 2 was essentially the same machine with a better keyboard and more easily expandable RAM.  Later CoCo 2s supported lower case text characters, unofficially.  Both of these early CoCos were essentially limited to 64KB of RAM.

In many ways, the CoCo 1 and 2 reminds one of the Apple II+.  Both machines really had a widespread maximum of 64KB of RAM.  They used 8-bit processors running at speeds close to each other.  Both machines can produce low resolution direct colors but really show detailed color images with NTSC composite artifact colors. If you subtract the purple/green combination from the Apple II, the graphics of a CoCo and an Apple can look very, very similar.  Both machines had somewhat limited (pre-IBM layout) keyboards and did not support lowercase characters officially.  Both came with ports for analog joysticks and cassette storage.  The sound hardware for each machine was rather crude and neglected.  Disk storage was only slightly better on the CoCo.

The CoCo 3 was a much more significant upgrade.  It came with double the CPU speed, 128KB of RAM and could be officially expanded to 512KB of RAM.  There were four extra keys on the keyboard.  It had new RGB-based graphics modes which could support 16 out of 64 pure colors and supported several higher resolutions in 2 colors (640x192), 4 colors (320x192 and 640x192) and 16 colors (320x192).